Pushing changes for testing harness before my next meeting. Adding working exec library and sample code

Signed-off-by: Kris Nóva <kris@nivenly.com>

examples/app_upload_download_photo.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	sampleapp "github.com/kris-nova/client-go/sample-app"
+	"github.com/kris-nova/logger"
+)
+
+func main() {
+	logger.Level = 4
+	app := sampleapp.New()
+	var err error
+	err = app.Start()
+	if err != nil {
+		logger.Critical(err.Error())
+	}
+	err = app.Stop()
+	if err != nil {
+		logger.Critical(err.Error())
+	}
+}